A series of 1,5-diaryl- and 1,8-diaryl-substituted anthraquinone dyes, which contain −COOH or −NH₂ groups, were prepared. The aryl-substituted anthraquinone dyes possess excellent thermostability and will keep their original colour in polycondensation with caprolactam at 260–280°C. With different aryl substituents the anthraquinone dyes exhibit different colours and can be used to prepare a series of coloured nylon-6 fibres. ©1997 SCI